Method for performing communication using TDD frame in wireless communication system, and device therefor

1. A method for performing communication by a user equipment using a time division duplex (TDD) frame including a plurality of self-contained subframes in a wireless communication system, wherein each of the plurality of self-contained subframes includes a downlink control zone, a data zone and an uplink control zone in sequence, the method comprising: receiving a first synchronization signal (SS) in a first symbol of a first subframe of the TDD frame, wherein the first subframe is a starting subframe among the plurality of self-contained subframes, and the first symbol of the first subframe is included in the downlink control zone of the first subframe; receiving a second SS consisting of L′ sequences in a first symbol of a second subframe of the TDD frame, and L′ is a natural number, wherein the first symbol of the second subframe includes L resource elements, and L is a natural number, wherein the second subframe is a second starting subframe among the plurality of self-contained subframes, and the first symbol of the second subframe is included in the downlink control zone of the second subframe; and receiving system information in only a first symbol of at least one subframe comprising a third subframe of the TDD frame, wherein the third subframe is a third starting subframe among the plurality of self-contained subframes, and the first symbol of the third subframe is included in the downlink control zone of the third subframe, based on the system information being further transmitted in each of only a first symbol of the plurality of the self-contained subframes located after the third subframe, decoding all the system information transmitted in the first symbol of the third subframe and each of the first symbol of the plurality of the self-contained subframes located after the third subframe together, wherein based on L being different from the L′ sequences are non-orthogonal sequences, wherein based on L being the same as the L′ sequences are orthogonal sequences, wherein the system information is only transmitted in the first symbol of the third subframe included in the downlink control zone of the third subframe and the first symbol of each of the plurality of the self-contained subframes included in the downlink control zone of the plurality of the self-contained subframe regardless of a size of the system information, and wherein based on the first SS only being transmitted on the first symbol of the first subframe and the second SS only being transmitted on the first symbol of the second subframe, the system information includes at least one of information for indicating the TDD frame, information for indicating a cyclic prefix (CP) duration and information for a filter index.

2. The method of claim 1 , further comprising the steps of: obtaining a physical cell identifier from the first SS and the second SS; performing channel estimation for a reference signal on the first symbol of the at least one subframe based on an obtained physical cell identifier based sequence; and decoding the system information based on information of the estimated channel.

3. The method of claim 1 , further comprising obtaining a cell index from the first SS; obtaining a physical cell group identifier from the second SS; and obtaining a physical cell identifier based on the obtained cell index and the obtained physical cell group identifier.

4. The method of claim 1 , further comprising: transmitting uplink control information through an uplink control zone containing at least one last symbol in the first subframe.

5. The method of claim 1 , wherein the first subframe and the second subframe are consecutive in time.

6. The method of claim 2 , wherein the decoding is performed after channel equalization is performed based on the information of the estimated channel.

7. A user equipment for performing communication using a time division duplex (TDD) frame including a plurality of self-contained subframes in a wireless communication system, wherein each of the plurality of self-contained subframes includes a downlink control zone, a data zone and an uplink control zone in sequence, the user equipment comprising: a receiver; and a processor, wherein the processor configured to: receive a first synchronization signal (SS) in a first symbol of a first subframe of the TDD frame, wherein the first subframe is a starting subframe among the plurality of self-contained subframes, and the first symbol of the first subframe is included in the downlink control zone of the first subframe, receive a second SS consisting of L′ sequences in a first symbol of a second subframe of the TDD frame, and L′ is a natural number, wherein the first symbol of the second subframe includes L resource elements, and L is a natural number, wherein the second subframe is a second starting subframe among the plurality of self-contained subframes, and the first symbol of the second subframe is included in the downlink control zone of the second subframe, and receive system information in only a first symbol of at least one subframe comprising a third subframe of the TDD frame, wherein the third subframe is a third starting subframe among the plurality of self-contained subframes, and the first symbol of the third subframe is included in the downlink control zone of the third subframe, based on the system information being further in each of only a first symbol of the plurality of the self-contained subframes located after the third subframe, decode all the system information transmitted in the first symbol of the third subframe and each of the first symbol of the plurality of the self-contained subframes located after the third subframe together, wherein based on L being different from L′, the L′ sequences are non-orthogonal sequences, wherein based on L being the same as the L′, the L′ sequences are orthogonal sequences, wherein the system information is only transmitted in the first symbol of the third subframe included in the downlink control zone of the third subframe and the first symbol of each of the plurality of the self-contained subframes included in the downlink control zone of the plurality of the self-contained subframe regardless of a size of the system information, and wherein based on the first SS only being transmitted on the first symbol of the first subframe and the second SS only being transmitted on the first symbol of the second subframe, the system information includes at least one of information for indicating the TDD frame, information for indicating a cyclic prefix (CP) duration and information for a filter index.

8. The user equipment of claim 7 , wherein the processor is configured to: obtain a physical cell identifier from the first SS and the second SS; perform channel estimation for a reference signal in the first symbol of the at least one subframe based on an obtained physical cell identifier based sequence; and decode the system information based on information of the estimated channel.

9. The user equipment of claim 7 , wherein the processor is further configured to perform decoding after channel equalization is performed based on information of the estimated channel.

10. The method of claim 1 , wherein each of the plurality of the self-contained subframes includes a guard period (GP) between the data zone and the uplink control zone, wherein the GP is configured to have a length of k*1, wherein k is a natural number, and wherein 1 is a length of a symbol included in the data zone.